High Performance Fibers (HPFs) are being proposed for expanding uses in many specialized applications, such as military and aerospace (turbo machinery, rockets, advanced structures), automobile, biomedical, energy, and other applications that require advanced materials with exceptional strength, stiffness, heat resistance, and/or chemical resistance. HPFs are sought when a combination of extreme material properties is required which cannot be met by existing metal filaments or by carbon, glass, vegetal or mineral fibers. HPF composite systems generally include a plurality of coated fibers, distributed within a “matrix.”
In most cases currently, fiber formation is accomplished by passing a liquid precursor through a spinneret. For example, FIG. 1 is a schematic representation of a spinneret, a plate with a pattern of tiny holes through which a liquid precursor is fed. Upon exit, the stream pattern gels into filaments called “green fibers”. The present inventors have concluded, however, that a better approach involves extracting fiber out of a laser focus where the fiber is created from surrounding fluid precursors. A laser is focused on the fiber tip thereby heating the fiber to temperatures at which the precursors dissociate and Chemical Vapor Deposition (CVD) takes place. The fiber grows in length and is pulled out of the reaction zone at the growth rate, resulting in the creation of an arbitrarily long monofilament fiber. This process technology is illustrated by FIG. 2. FIG. 2 is a schematic of an exemplary process as follows including a reactor 10; enlarged cutout view of reactor chamber 20; enlarged view of growth region 30. A self-seeded fiber 50 grows towards an oncoming coaxial laser 60 and is extracted through an extrusion microtube 40. CVD precursors are injected into the reaction zone from the extrusion microtube forming a small high concentration plume around the reaction zone that feeds and convectively enhances growth. This plume is embedded in a coaxial flow of inert gas that shields the reaction and carries away diluted by-products. This reactor design builds upon understanding of Laser Induced Chemical Vapor Deposition (LCVD) fiber growth. It provides a unique and valuable materials science laboratory, suited for rapid experimental development of specialty filaments. It may be, however, unfit for large scale manufacturing.
As in the microelectronics fabrication industry, where features are massively replicated using optical (photolithographic) methods, large scale replication of fiber growth is herein proposed. Pure optical parallelization for fiber growth is one approach to mass production of fibers. For example, a parallelization of the process technology illustrated by FIG. 2 can be pursued.
In pursuing large scale manufacturing objectives, however, certain features of the FIG. 2 approach should be preserved, such as:                Feature 1—Convection enhanced high-pressure precursor flow—has been shown to optimize single fiber growth.        Feature 2—Imaging at wavelengths that are specific to byproducts (e.g. Hydrogen at 656 nm)—provides for direct observability of fiber growth and has been used for process control.        Feature 3 and 4 respectively—Containerless and Material-agnostic—form the basis for a platform technology capable of processing a wide range of materials.        
A legitimate approach to laser foci multiplication is diffraction gratings. Diffraction gratings represent a well-established technology, present even in consumer items such as laser pointers, where they have the ability to generate a multitude of patterns. But if generating a prescribed pattern is commonplace, generating a large number of high quality, evenly distributed foci is a much harder problem, to which the present invention is directed.